ACM – Requesting Public Certificates

Steps

1. Specify Domain Names
• FQDN (e.g., app.example.com)
• Wildcard (e.g., .example.com) to cover all subdomains.

2. Choose Validation Method
• DNS Validation (recommended for automation): Add a provided CNAME record to your DNS (Route 53 or other).
• Email Validation: Confirm via an email sent to WHOIS or common admin addresses.

3. Complete Verification
• DNS or email validation may take minutes to hours.
• Certificate is issued after successful validation.

4. Automatic Renewal
• Renewals start 60 days before expiration.
• ACM handles renewals for certificates it issued.

Best Practices

• Prefer DNS validation for easier automation and scalability.

• Keep DNS management access ready, especially for external DNS providers.

• Use CloudWatch metrics or the ACM console to track certificate status.